def a():
    a=int(input(""))
    b=0.00001#0.0000001
    n=0
    d=0
    while n<10000000000:#4#6
        n+=1
        if d*d<a:
            d+=b
        elif d*d>a:
            print(f"{d-b}-{d}")
            break
def b():
    a=int(input())
    b=int(input())
    c=int(input())
    d=b/c
    n=0
    e=0
    while n<100000000:
        n+=1
        if e*e<a:
            e+=d
        else:
            print(f"{e-d}-{e}")
            break
def c():
    a=int(input())
    b=1
    n=0
    c=0
    x=1000
    while n<x:
        n+=1
        if c**2<a:
            c+=b
        if c**2==a:
            print(c)
            break
        if c**2>a:
            c-=b
            b=b/10
    if n==x:
        print(c)
c()



"""

a=0
b=1
n=0
while n<10000:
    if 10**a<20:
        a+=b
    if 10**a==20:
        n=10000
    if 10**a>20:
        a-=b
        b=b/10
    n+=1
print(a)
c=a
a=0
b=1
n=0
while n<10000:
    if 100**a<50:
        a+=b
    if 100**a==50:
        n=10000
    if 100**a>50:
        a-=b
        b=b/10
    n+=1
print(a)

c=c/2
print(c+a+1.5)"""